Process for the production of optionally-foamed polyurethanes

Abstract

This invention relates to a process for the production of polyurethanes, particularly polyurethane foam moldings having a compact skin and a cellular core, using special tin activators.

What is claimed is: 
     
       1. A process for the production of optionally-foamed polyurethanes comprising reacting polyisocyanates with organic compounds containing at least two isocyanate-reactive hydrogen atoms and having molecular weights from 400 to 10,000 in the presence of activators, characterized in that the activators used are compounds corresponding to the general formula: ##STR14## in which R and R 1  may be the same or different and represent C 1  -C 20  -alkyl, C 5  -C 7  -cycloalkyl or C 7  -C 30  -alkaryl radicals; Hal represents a halogen atom;   R 2  represents a halogen atom;   R 2  represents a saturated aliphatic radical containing from 1 to 30 carbon atoms; an unsaturated aliphatic radical containing from 2 to 18 carbon atoms; a cycloaliphatic radical containing from 4 to 7 carbon atoms; or an aromatic radical containing from 6 to 14 carbon atoms;   X represents hydrogen or a group corresponding to the formula ##STR15##  and n is an integer of from 1 to 3.   
     
     
       2. A process according to claim 1, characterized in that, Hal is a chlorine atom. 
     
     
       3. A process according to claim 1, characterized in that the activators are used in a quantity of from 0.05 to 5% by weight, based on the compounds containing at least 2 active hydrogen atoms and having molecular weights in the range from 400 to 10,000. 
     
     
       4. A process according to claim 1 or claim 3, characterized in that foam moldings having a compact skin and a cellular core are produced. 
     
     
       5. A process as claimed in claim 1 or claim 3, characterized in that aliphatic and/or alicyclic polyisocyanates are used as the polyisocyanates.